ARCUS | Arctic Research Consortium of the United States

7th Annual ARCUS Award for Arctic Research Excellence


Submitted by   Maria Sergeeva
Authors   Maria Sergeeva and D. V. Blagoveschensky
Category   Physical Science
Title   Substorm Effects on High-Latitude HF Paths of the Oblique Ionospheric Sounding
Affiliation   Radioengineering, State University Of Aerospace Instrumentation, St.Petersburg , Russian Federation

Abstract

The behaviour of the oblique ionospheric sounding parameters such as MOF (the maximum observed frequency) and LOF (the lowest observed frequency) were considered simultaneously on three high-latitude HF paths during the periods of isolated magnetospheric substorms. The mentioned parameters characterize the state of the upper and lower polar ionosphere during the disturbances, whereas the data from the vertical sounding are poor or absent. The reflection points of the paths shifted in latitude by 5° are located at different areas of the region of the increased ionization and are influenced by the polar edge of the main ionospheric trough, the auroral oval and the irregularities' ring on the border of the oval and the polar cap. Specific tendencies of MOF and LOF variations were obtained for each of the radio paths with the point of view of physical phenomena. Considerations useful to organize the radio communications at high latitudes during substorms are formulated.